Improved dynamic characteristics on four-wave mixing wavelength conversion in light-holding SOAs

We investigate theoretically and experimentally the dynamic characteristics of the wavelength conversion that is based on four-wave mixing (FWM) in a light-holding semiconductor optical amplifier (LHSOA). Two FWM conversion techniques, including the single-pump (SP) and two orthogonal-polarized pumps (OPP) schemes, are investigated using a sophisticated time-domain simulation model. The simulation indicates that the holding light gives an improved eye opening and signal-to-noise ratio for both the SP and OPP schemes. The chirp response for both schemes are also presented. The performance improvement are verified from dynamic measurements such as eye diagram and bit-error-rate (BER) tests. Clearer eye openings and reduced power penalties are obtained with the injection of a holding light. By comparing to the experimental results, we also prove that our numerical modeling can predict the device performance and can be used for optimizing the wavelength conversion process.